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authorLinus Torvalds <torvalds@linux-foundation.org>2020-02-04 13:06:46 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-04 13:06:46 +0000
commit71c3a888cbcaf453aecf8d2f8fb003271d28073f (patch)
tree9895a04a40c39db585d2e1a0553bbc79d4b0b084 /Documentation
parent153b5c566d30fb984827acb12fd93c3aa6c147d3 (diff)
parent4c25df5640ae6e4491ee2c50d3f70c1559ef037d (diff)
downloadlinux-stericsson-71c3a888cbcaf453aecf8d2f8fb003271d28073f.tar.gz
Merge tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman: "A pretty small batch for us, and apologies for it being a bit late, I wanted to sneak Christophe's user_access_begin() series in. Summary: - Implement user_access_begin() and friends for our platforms that support controlling kernel access to userspace. - Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx. - Some tweaks to our pseries IOMMU code to allow SVMs ("secure" virtual machines) to use the IOMMU. - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit VDSO, and some other improvements. - A series to use the PCI hotplug framework to control opencapi card's so that they can be reset and re-read after flashing a new FPGA image. As well as other minor fixes and improvements as usual. Thanks to: Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen Zhou, Christophe Leroy, Frederic Barrat, Greg Kurz, Jason A. Donenfeld, Joel Stanley, Jordan Niethe, Julia Lawall, Krzysztof Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus Walleij, Michael Bringmann, Nathan Chancellor, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy Dunlap, Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain" * tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (131 commits) powerpc: configs: Cleanup old Kconfig options powerpc/configs/skiroot: Enable some more hardening options powerpc/configs/skiroot: Disable xmon default & enable reboot on panic powerpc/configs/skiroot: Enable security features powerpc/configs/skiroot: Update for symbol movement only powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV powerpc/configs/skiroot: Drop HID_LOGITECH powerpc/configs: Drop NET_VENDOR_HP which moved to staging powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE powerpc/configs: Drop CONFIG_QLGE which moved to staging powerpc: Do not consider weak unresolved symbol relocations as bad powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACK powerpc: indent to improve Kconfig readability powerpc: Provide initial documentation for PAPR hcalls powerpc: Implement user_access_save() and user_access_restore() powerpc: Implement user_access_begin and friends powerpc/32s: Prepare prevent_user_access() for user_access_end() powerpc/32s: Drop NULL addr verification powerpc/kuap: Fix set direction in allow/prevent_user_access() powerpc/32s: Fix bad_kuap_fault() ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/spi/fsl-spi.txt8
-rw-r--r--Documentation/powerpc/imc.rst199
-rw-r--r--Documentation/powerpc/index.rst2
-rw-r--r--Documentation/powerpc/papr_hcalls.rst250
4 files changed, 455 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/spi/fsl-spi.txt b/Documentation/devicetree/bindings/spi/fsl-spi.txt
index 411375eac54d..0654380eb751 100644
--- a/Documentation/devicetree/bindings/spi/fsl-spi.txt
+++ b/Documentation/devicetree/bindings/spi/fsl-spi.txt
@@ -15,13 +15,13 @@ Required properties:
- clock-frequency : input clock frequency to non FSL_SOC cores
Optional properties:
-- gpios : specifies the gpio pins to be used for chipselects.
+- cs-gpios : specifies the gpio pins to be used for chipselects.
The gpios will be referred to as reg = <index> in the SPI child nodes.
If unspecified, a single SPI device without a chip select can be used.
- fsl,spisel_boot : for the MPC8306 and MPC8309, specifies that the
SPISEL_BOOT signal is used as chip select for a slave device. Use
reg = <number of gpios> in the corresponding child node, i.e. 0 if
- the gpios property is not present.
+ the cs-gpios property is not present.
Example:
spi@4c0 {
@@ -31,8 +31,8 @@ Example:
interrupts = <82 0>;
interrupt-parent = <700>;
mode = "cpu";
- gpios = <&gpio 18 1 // device reg=<0>
- &gpio 19 1>; // device reg=<1>
+ cs-gpios = <&gpio 18 1 // device reg=<0>
+ &gpio 19 1>; // device reg=<1>
};
diff --git a/Documentation/powerpc/imc.rst b/Documentation/powerpc/imc.rst
new file mode 100644
index 000000000000..633bcee7dc85
--- /dev/null
+++ b/Documentation/powerpc/imc.rst
@@ -0,0 +1,199 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. _imc:
+
+===================================
+IMC (In-Memory Collection Counters)
+===================================
+
+Anju T Sudhakar, 10 May 2019
+
+.. contents::
+ :depth: 3
+
+
+Basic overview
+==============
+
+IMC (In-Memory collection counters) is a hardware monitoring facility that
+collects large numbers of hardware performance events at Nest level (these are
+on-chip but off-core), Core level and Thread level.
+
+The Nest PMU counters are handled by a Nest IMC microcode which runs in the OCC
+(On-Chip Controller) complex. The microcode collects the counter data and moves
+the nest IMC counter data to memory.
+
+The Core and Thread IMC PMU counters are handled in the core. Core level PMU
+counters give us the IMC counters' data per core and thread level PMU counters
+give us the IMC counters' data per CPU thread.
+
+OPAL obtains the IMC PMU and supported events information from the IMC Catalog
+and passes on to the kernel via the device tree. The event's information
+contains:
+
+- Event name
+- Event Offset
+- Event description
+
+and possibly also:
+
+- Event scale
+- Event unit
+
+Some PMUs may have a common scale and unit values for all their supported
+events. For those cases, the scale and unit properties for those events must be
+inherited from the PMU.
+
+The event offset in the memory is where the counter data gets accumulated.
+
+IMC catalog is available at:
+ https://github.com/open-power/ima-catalog
+
+The kernel discovers the IMC counters information in the device tree at the
+`imc-counters` device node which has a compatible field
+`ibm,opal-in-memory-counters`. From the device tree, the kernel parses the PMUs
+and their event's information and register the PMU and its attributes in the
+kernel.
+
+IMC example usage
+=================
+
+.. code-block:: sh
+
+ # perf list
+ [...]
+ nest_mcs01/PM_MCS01_64B_RD_DISP_PORT01/ [Kernel PMU event]
+ nest_mcs01/PM_MCS01_64B_RD_DISP_PORT23/ [Kernel PMU event]
+ [...]
+ core_imc/CPM_0THRD_NON_IDLE_PCYC/ [Kernel PMU event]
+ core_imc/CPM_1THRD_NON_IDLE_INST/ [Kernel PMU event]
+ [...]
+ thread_imc/CPM_0THRD_NON_IDLE_PCYC/ [Kernel PMU event]
+ thread_imc/CPM_1THRD_NON_IDLE_INST/ [Kernel PMU event]
+
+To see per chip data for nest_mcs0/PM_MCS_DOWN_128B_DATA_XFER_MC0/:
+
+.. code-block:: sh
+
+ # ./perf stat -e "nest_mcs01/PM_MCS01_64B_WR_DISP_PORT01/" -a --per-socket
+
+To see non-idle instructions for core 0:
+
+.. code-block:: sh
+
+ # ./perf stat -e "core_imc/CPM_NON_IDLE_INST/" -C 0 -I 1000
+
+To see non-idle instructions for a "make":
+
+.. code-block:: sh
+
+ # ./perf stat -e "thread_imc/CPM_NON_IDLE_PCYC/" make
+
+
+IMC Trace-mode
+===============
+
+POWER9 supports two modes for IMC which are the Accumulation mode and Trace
+mode. In Accumulation mode, event counts are accumulated in system Memory.
+Hypervisor then reads the posted counts periodically or when requested. In IMC
+Trace mode, the 64 bit trace SCOM value is initialized with the event
+information. The CPMCxSEL and CPMC_LOAD in the trace SCOM, specifies the event
+to be monitored and the sampling duration. On each overflow in the CPMCxSEL,
+hardware snapshots the program counter along with event counts and writes into
+memory pointed by LDBAR.
+
+LDBAR is a 64 bit special purpose per thread register, it has bits to indicate
+whether hardware is configured for accumulation or trace mode.
+
+LDBAR Register Layout
+---------------------
+
+ +-------+----------------------+
+ | 0 | Enable/Disable |
+ +-------+----------------------+
+ | 1 | 0: Accumulation Mode |
+ | +----------------------+
+ | | 1: Trace Mode |
+ +-------+----------------------+
+ | 2:3 | Reserved |
+ +-------+----------------------+
+ | 4-6 | PB scope |
+ +-------+----------------------+
+ | 7 | Reserved |
+ +-------+----------------------+
+ | 8:50 | Counter Address |
+ +-------+----------------------+
+ | 51:63 | Reserved |
+ +-------+----------------------+
+
+TRACE_IMC_SCOM bit representation
+---------------------------------
+
+ +-------+------------+
+ | 0:1 | SAMPSEL |
+ +-------+------------+
+ | 2:33 | CPMC_LOAD |
+ +-------+------------+
+ | 34:40 | CPMC1SEL |
+ +-------+------------+
+ | 41:47 | CPMC2SEL |
+ +-------+------------+
+ | 48:50 | BUFFERSIZE |
+ +-------+------------+
+ | 51:63 | RESERVED |
+ +-------+------------+
+
+CPMC_LOAD contains the sampling duration. SAMPSEL and CPMCxSEL determines the
+event to count. BUFFERSIZE indicates the memory range. On each overflow,
+hardware snapshots the program counter along with event counts and updates the
+memory and reloads the CMPC_LOAD value for the next sampling duration. IMC
+hardware does not support exceptions, so it quietly wraps around if memory
+buffer reaches the end.
+
+*Currently the event monitored for trace-mode is fixed as cycle.*
+
+Trace IMC example usage
+=======================
+
+.. code-block:: sh
+
+ # perf list
+ [....]
+ trace_imc/trace_cycles/ [Kernel PMU event]
+
+To record an application/process with trace-imc event:
+
+.. code-block:: sh
+
+ # perf record -e trace_imc/trace_cycles/ yes > /dev/null
+ [ perf record: Woken up 1 times to write data ]
+ [ perf record: Captured and wrote 0.012 MB perf.data (21 samples) ]
+
+The `perf.data` generated, can be read using perf report.
+
+Benefits of using IMC trace-mode
+================================
+
+PMI (Performance Monitoring Interrupts) interrupt handling is avoided, since IMC
+trace mode snapshots the program counter and updates to the memory. And this
+also provide a way for the operating system to do instruction sampling in real
+time without PMI processing overhead.
+
+Performance data using `perf top` with and without trace-imc event.
+
+PMI interrupts count when `perf top` command is executed without trace-imc event.
+
+.. code-block:: sh
+
+ # grep PMI /proc/interrupts
+ PMI: 0 0 0 0 Performance monitoring interrupts
+ # ./perf top
+ ...
+ # grep PMI /proc/interrupts
+ PMI: 39735 8710 17338 17801 Performance monitoring interrupts
+ # ./perf top -e trace_imc/trace_cycles/
+ ...
+ # grep PMI /proc/interrupts
+ PMI: 39735 8710 17338 17801 Performance monitoring interrupts
+
+
+That is, the PMI interrupt counts do not increment when using the `trace_imc` event.
diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst
index ba5edb3211c0..0d45f0fc8e57 100644
--- a/Documentation/powerpc/index.rst
+++ b/Documentation/powerpc/index.rst
@@ -18,9 +18,11 @@ powerpc
elfnote
firmware-assisted-dump
hvcs
+ imc
isa-versions
kaslr-booke32
mpc52xx
+ papr_hcalls
pci_iov_resource_on_powernv
pmu-ebb
ptrace
diff --git a/Documentation/powerpc/papr_hcalls.rst b/Documentation/powerpc/papr_hcalls.rst
new file mode 100644
index 000000000000..3493631a60f8
--- /dev/null
+++ b/Documentation/powerpc/papr_hcalls.rst
@@ -0,0 +1,250 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+Hypercall Op-codes (hcalls)
+===========================
+
+Overview
+=========
+
+Virtualization on 64-bit Power Book3S Platforms is based on the PAPR
+specification [1]_ which describes the run-time environment for a guest
+operating system and how it should interact with the hypervisor for
+privileged operations. Currently there are two PAPR compliant hypervisors:
+
+- **IBM PowerVM (PHYP)**: IBM's proprietary hypervisor that supports AIX,
+ IBM-i and Linux as supported guests (termed as Logical Partitions
+ or LPARS). It supports the full PAPR specification.
+
+- **Qemu/KVM**: Supports PPC64 linux guests running on a PPC64 linux host.
+ Though it only implements a subset of PAPR specification called LoPAPR [2]_.
+
+On PPC64 arch a guest kernel running on top of a PAPR hypervisor is called
+a *pSeries guest*. A pseries guest runs in a supervisor mode (HV=0) and must
+issue hypercalls to the hypervisor whenever it needs to perform an action
+that is hypervisor priviledged [3]_ or for other services managed by the
+hypervisor.
+
+Hence a Hypercall (hcall) is essentially a request by the pseries guest
+asking hypervisor to perform a privileged operation on behalf of the guest. The
+guest issues a with necessary input operands. The hypervisor after performing
+the privilege operation returns a status code and output operands back to the
+guest.
+
+HCALL ABI
+=========
+The ABI specification for a hcall between a pseries guest and PAPR hypervisor
+is covered in section 14.5.3 of ref [2]_. Switch to the Hypervisor context is
+done via the instruction **HVCS** that expects the Opcode for hcall is set in *r3*
+and any in-arguments for the hcall are provided in registers *r4-r12*. If values
+have to be passed through a memory buffer, the data stored in that buffer should be
+in Big-endian byte order.
+
+Once control is returns back to the guest after hypervisor has serviced the
+'HVCS' instruction the return value of the hcall is available in *r3* and any
+out values are returned in registers *r4-r12*. Again like in case of in-arguments,
+any out values stored in a memory buffer will be in Big-endian byte order.
+
+Powerpc arch code provides convenient wrappers named **plpar_hcall_xxx** defined
+in a arch specific header [4]_ to issue hcalls from the linux kernel
+running as pseries guest.
+
+Register Conventions
+====================
+
+Any hcall should follow same register convention as described in section 2.2.1.1
+of "64-Bit ELF V2 ABI Specification: Power Architecture"[5]_. Table below
+summarizes these conventions:
+
++----------+----------+-------------------------------------------+
+| Register |Volatile | Purpose |
+| Range |(Y/N) | |
++==========+==========+===========================================+
+| r0 | Y | Optional-usage |
++----------+----------+-------------------------------------------+
+| r1 | N | Stack Pointer |
++----------+----------+-------------------------------------------+
+| r2 | N | TOC |
++----------+----------+-------------------------------------------+
+| r3 | Y | hcall opcode/return value |
++----------+----------+-------------------------------------------+
+| r4-r10 | Y | in and out values |
++----------+----------+-------------------------------------------+
+| r11 | Y | Optional-usage/Environmental pointer |
++----------+----------+-------------------------------------------+
+| r12 | Y | Optional-usage/Function entry address at |
+| | | global entry point |
++----------+----------+-------------------------------------------+
+| r13 | N | Thread-Pointer |
++----------+----------+-------------------------------------------+
+| r14-r31 | N | Local Variables |
++----------+----------+-------------------------------------------+
+| LR | Y | Link Register |
++----------+----------+-------------------------------------------+
+| CTR | Y | Loop Counter |
++----------+----------+-------------------------------------------+
+| XER | Y | Fixed-point exception register. |
++----------+----------+-------------------------------------------+
+| CR0-1 | Y | Condition register fields. |
++----------+----------+-------------------------------------------+
+| CR2-4 | N | Condition register fields. |
++----------+----------+-------------------------------------------+
+| CR5-7 | Y | Condition register fields. |
++----------+----------+-------------------------------------------+
+| Others | N | |
++----------+----------+-------------------------------------------+
+
+DRC & DRC Indexes
+=================
+::
+
+ DR1 Guest
+ +--+ +------------+ +---------+
+ | | <----> | | | User |
+ +--+ DRC1 | | DRC | Space |
+ | PAPR | Index +---------+
+ DR2 | Hypervisor | | |
+ +--+ | | <-----> | Kernel |
+ | | <----> | | Hcall | |
+ +--+ DRC2 +------------+ +---------+
+
+PAPR hypervisor terms shared hardware resources like PCI devices, NVDIMMs etc
+available for use by LPARs as Dynamic Resource (DR). When a DR is allocated to
+an LPAR, PHYP creates a data-structure called Dynamic Resource Connector (DRC)
+to manage LPAR access. An LPAR refers to a DRC via an opaque 32-bit number
+called DRC-Index. The DRC-index value is provided to the LPAR via device-tree
+where its present as an attribute in the device tree node associated with the
+DR.
+
+HCALL Return-values
+===================
+
+After servicing the hcall, hypervisor sets the return-value in *r3* indicating
+success or failure of the hcall. In case of a failure an error code indicates
+the cause for error. These codes are defined and documented in arch specific
+header [4]_.
+
+In some cases a hcall can potentially take a long time and need to be issued
+multiple times in order to be completely serviced. These hcalls will usually
+accept an opaque value *continue-token* within there argument list and a
+return value of *H_CONTINUE* indicates that hypervisor hasn't still finished
+servicing the hcall yet.
+
+To make such hcalls the guest need to set *continue-token == 0* for the
+initial call and use the hypervisor returned value of *continue-token*
+for each subsequent hcall until hypervisor returns a non *H_CONTINUE*
+return value.
+
+HCALL Op-codes
+==============
+
+Below is a partial list of HCALLs that are supported by PHYP. For the
+corresponding opcode values please look into the arch specific header [4]_:
+
+**H_SCM_READ_METADATA**
+
+| Input: *drcIndex, offset, buffer-address, numBytesToRead*
+| Out: *numBytesRead*
+| Return Value: *H_Success, H_Parameter, H_P2, H_P3, H_Hardware*
+
+Given a DRC Index of an NVDIMM, read N-bytes from the the metadata area
+associated with it, at a specified offset and copy it to provided buffer.
+The metadata area stores configuration information such as label information,
+bad-blocks etc. The metadata area is located out-of-band of NVDIMM storage
+area hence a separate access semantics is provided.
+
+**H_SCM_WRITE_METADATA**
+
+| Input: *drcIndex, offset, data, numBytesToWrite*
+| Out: *None*
+| Return Value: *H_Success, H_Parameter, H_P2, H_P4, H_Hardware*
+
+Given a DRC Index of an NVDIMM, write N-bytes to the metadata area
+associated with it, at the specified offset and from the provided buffer.
+
+**H_SCM_BIND_MEM**
+
+| Input: *drcIndex, startingScmBlockIndex, numScmBlocksToBind,*
+| *targetLogicalMemoryAddress, continue-token*
+| Out: *continue-token, targetLogicalMemoryAddress, numScmBlocksToBound*
+| Return Value: *H_Success, H_Parameter, H_P2, H_P3, H_P4, H_Overlap,*
+| *H_Too_Big, H_P5, H_Busy*
+
+Given a DRC-Index of an NVDIMM, map a continuous SCM blocks range
+*(startingScmBlockIndex, startingScmBlockIndex+numScmBlocksToBind)* to the guest
+at *targetLogicalMemoryAddress* within guest physical address space. In
+case *targetLogicalMemoryAddress == 0xFFFFFFFF_FFFFFFFF* then hypervisor
+assigns a target address to the guest. The HCALL can fail if the Guest has
+an active PTE entry to the SCM block being bound.
+
+**H_SCM_UNBIND_MEM**
+| Input: drcIndex, startingScmLogicalMemoryAddress, numScmBlocksToUnbind
+| Out: numScmBlocksUnbound
+| Return Value: *H_Success, H_Parameter, H_P2, H_P3, H_In_Use, H_Overlap,*
+| *H_Busy, H_LongBusyOrder1mSec, H_LongBusyOrder10mSec*
+
+Given a DRC-Index of an NVDimm, unmap *numScmBlocksToUnbind* SCM blocks starting
+at *startingScmLogicalMemoryAddress* from guest physical address space. The
+HCALL can fail if the Guest has an active PTE entry to the SCM block being
+unbound.
+
+**H_SCM_QUERY_BLOCK_MEM_BINDING**
+
+| Input: *drcIndex, scmBlockIndex*
+| Out: *Guest-Physical-Address*
+| Return Value: *H_Success, H_Parameter, H_P2, H_NotFound*
+
+Given a DRC-Index and an SCM Block index return the guest physical address to
+which the SCM block is mapped to.
+
+**H_SCM_QUERY_LOGICAL_MEM_BINDING**
+
+| Input: *Guest-Physical-Address*
+| Out: *drcIndex, scmBlockIndex*
+| Return Value: *H_Success, H_Parameter, H_P2, H_NotFound*
+
+Given a guest physical address return which DRC Index and SCM block is mapped
+to that address.
+
+**H_SCM_UNBIND_ALL**
+
+| Input: *scmTargetScope, drcIndex*
+| Out: *None*
+| Return Value: *H_Success, H_Parameter, H_P2, H_P3, H_In_Use, H_Busy,*
+| *H_LongBusyOrder1mSec, H_LongBusyOrder10mSec*
+
+Depending on the Target scope unmap all SCM blocks belonging to all NVDIMMs
+or all SCM blocks belonging to a single NVDIMM identified by its drcIndex
+from the LPAR memory.
+
+**H_SCM_HEALTH**
+
+| Input: drcIndex
+| Out: *health-bitmap, health-bit-valid-bitmap*
+| Return Value: *H_Success, H_Parameter, H_Hardware*
+
+Given a DRC Index return the info on predictive failure and overall health of
+the NVDIMM. The asserted bits in the health-bitmap indicate a single predictive
+failure and health-bit-valid-bitmap indicate which bits in health-bitmap are
+valid.
+
+**H_SCM_PERFORMANCE_STATS**
+
+| Input: drcIndex, resultBuffer Addr
+| Out: None
+| Return Value: *H_Success, H_Parameter, H_Unsupported, H_Hardware, H_Authority, H_Privilege*
+
+Given a DRC Index collect the performance statistics for NVDIMM and copy them
+to the resultBuffer.
+
+References
+==========
+.. [1] "Power Architecture Platform Reference"
+ https://en.wikipedia.org/wiki/Power_Architecture_Platform_Reference
+.. [2] "Linux on Power Architecture Platform Reference"
+ https://members.openpowerfoundation.org/document/dl/469
+.. [3] "Definitions and Notation" Book III-Section 14.5.3
+ https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0
+.. [4] arch/powerpc/include/asm/hvcall.h
+.. [5] "64-Bit ELF V2 ABI Specification: Power Architecture"
+ https://openpowerfoundation.org/?resource_lib=64-bit-elf-v2-abi-specification-power-architecture